This invention relates to the field of telecommunications, and more specifically, to detection of specialized calls, such as data calls in telecommunication systems, and to differential billing for data and voice calls.
For many year it has been the policy in the United States and Canada to provide telecommunications service and to make billing for such services independent of the content of the communication. While this policy has served admirably to support the building of universal voice telephone service and to expand greatly the use of the telecommunications network for data services, there are signs that this type of policy may no longer be as strongly favored by the regulatory authorities. One sign of such discrimination has been a recent decision in Canada to have a different inter-carrier compensation for a data call than for a voice call, provided the originating carrier can demonstrate that a call is a data call. Regulatory and social factors which may influence separate treatment of such calls are the different economic and/or social values of data calls as contrasted with voice calls. There still is a very strong pressure to minimize charges for minimum local service and to insure that even high usage local service remains within the economic means of the elderly or the poor. For example, it is possible that a different time sensitive tariff may be imposed on short haul data calls.
A partial solution to this problem has been implemented in some cases by examining the destination number of telephone calls as part of the bill calculation process; this process then distinguishes calls known on the basis of the called number to be data calls from other calls and therefore gives such calls appropriate billing treatment. This solution is quite unsatisfactory because so many, even of the frequently used data destinations, are not announced by their customers as being data destinations, and therefore escape whatever negative effect an identification of a call through these destinations would have on the callers.
Another partial solution is provided by monitoring out of band signalling calls. However, this only detects a fraction of the data calls currently being made.
Another serious problem, however, is that on-line or Internet service providers are offering monthly flat fee packages. As a result, data users are staying on a telephone line for hours or even days at a time. On the other hand, the current telephone network is designed for voice calls, which average two minutes. Thus, the voice telephone network is highly concentrated so that expensive capital equipment is not purchased and then used minimally. These assumptions are no longer fully valid. With more and more people using telephone lines for data services, and these people are staying on-line for longer periods of time, the network occasionally (and more and more frequently) becomes congested, and some customers do not receive service, or even dial tone. This may be disastrous in the event of an emergency.
We have recognized that a problem of the prior art is that a satisfactory and economical arrangement for distinguishing between in-band signalled data calls and voice calls on a per call basis, and for charging differently for data calls does not exist.
The above problem is solved and an advance is made over the prior art in accordance with this invention wherein data calls are identified by connecting a signal detector during or subsequent to the establishment of a connection and the recognition of an answer signal by the called station. Advantageously, the holding time of such a signal detector which is connected on every call is small so that the cost is kept low. After a determination of a data or a voice call is made, then the call can be billed so that a traditional voice call is treated according to the prior art, but the data call is billed differently, either according to time, or with a higher charge, or both. With such charges possible, it is also possible to offer flat rate data service with a much higher flat rate charge.
In accordance with one aspect of Applicants"" invention, a signal detector is implemented using a signal processor capable of examining the digit stream representing the signal generated by callers and called customers for many calls simultaneously. Advantageously, this type of arrangement sharply reduces the cost of the tone detection process.
Advantageously, these arrangements allow for a billing mark to be entered on every call record for a data call, thus simplifying the processing of these billing records to produce customer statements. In accordance with another feature of this invention, a data set is adapted to provide an initial tone. Advantageously, this arrangement permits a data call to be recognized immediately and allows vertical services, such as the use of specially conditioned transmission facilities, to be readily implemented.
In Applicants"" preferred embodiment, an enhanced digit detector detects the tone signals characteristic of a data call. If such signals are not detected, the call is determined to be a voice call, and normal local billing procedures may be used. If a data call is detected, then usage based charges such as those often used for long distance calls or, alternatively, some minimum special charge, may be used; alternatively, the regular voice billing charge can be used for a data call shorter than a pre-specified limit. Advantageously, voice calls may be rechecked for data at random or predetermined intervals to prevent fraud and thus, enhance revenue and discourage unnecessary usage of the telephone network.
These arrangements can also be used to further discriminate among data type calls, e.g., to distinguish from Internet usage from facsimile calls, provided that each type call has a characteristic signal or set of signals. Each distinguishable type of call may be billed with its own billing rate scheme. For example, Internet type calls may be billed on a per-minute basis, while a first portion, e.g., the first ten minutes, of a long facsimile call may be free or may cost a single unit if the caller has unlimited duration voice calling in a particular area, and may be billed thereafter at a per-minute facsimile rate.